The project was originally envisioned as a reunion between Requa and Ficarra's "Crazy, Stupid, Love" stars Ryan Gosling and Emma Stone, who had sizzling chemistry in that 2011 comedy. Scheduling issues prevented that pairing, and while the idea of pairing red-hot Affleck with Stewart was certainly intriguing, prior commitments kept the "Argo" star from closing a deal, prompting Warner Bros. to seek another A-list leading man.

The understandably selective Smith had been weighing several projects, including WB's "The Accountant," for his next move, and the prospect of doing an original movie that can showcase his strengths appealed to him, thus the commitment to "Focus."

Smith is represented by CAA, and Variety first reported the news of his casting.